With the continuous development of the manufacturing technology of integrated circuits (ICs), the integration level and performance requirements of the ICs have become higher and higher. In order to increase the integration level and reduce the production cost, the critical dimension (CD) of the devices in ICs has become smaller and smaller; and the device density inside the ICs has become larger and larger. Such developments have caused the surface of a wafer to be unable to provide enough area to form interconnect lines. To match the needs for the interconnect lines after the CD is reduced, the electrical connections among different metal layers and/or the electrical connections between the metal layers and the wafer (or substrate) are realized by interconnect structures.
The metal materials used for forming the interconnect structure are usually difficult to adhere to semiconductor materials of the device structures. Thus, a glue layer is usually formed on the semiconductor material before forming the interconnect structure. The glue layer is used to increase the interconnect strength between the metal interconnect structure and the semiconductor material.
However, the glue layer formed by existing techniques is often easy to peel off, and/or to have bubbles. Such defects may affect the performance of the semiconductor devices. The disclosed device structures, methods and apparatus are directed to solve one or more problems set forth above and other problems in the art.